TABLE 1.
Neurological disorders associated with olfactory loss.
| Neurological disorder | References | N | Olfactory test |
| 22q11 deletion syndrome | Sobin et al., 2006 | 62 | UPSIT |
| Agnosia | Kopala and Clark, 1990 | 77 | UPSIT |
| Alcoholism | Rupp et al., 2004 | 60 | Sniffin’ Sticks |
| Alzheimer’s disease | Waldton, 1974 | 100 | Odor identification test |
| Amyotrophic lateral sclerosis | Viguera et al., 2018 | 147 | UPSIT |
| Anesthesia cognitive impairment | Zhang et al., 2022 | 242 | Sniffin’ Sticks |
| Anorexia | Roessner et al., 2005 | 32 | Sniffin’ Sticks |
| Anxiety | Chen X. et al., 2021 | 107 | Sniffin’ Sticks |
| Autism | Kinnaird et al., 2020 | 80 | Sniffin’ Sticks |
| Autoimmune encephalitis | Geran et al., 2019 | 64 | Sniffin’ Sticks |
| Bardet-Biedl syndrome | Iannaccone et al., 2005 | 15 | UPSIT |
| Bipolar disorder | Kazour et al., 2020 | 176 | Odor identification, odor discrimination |
| Blepharospasm | Gamain et al., 2021 | 34 | Sniffin’ Sticks |
| Cerebral palsy | Nakashima et al., 2019 | 14 | Japanese odor stick identification test |
| Chagas’ disease | Leon-Sarmiento et al., 2014 | 120 | UPSIT |
| Childhood maltreatment | Croy et al., 2010 | 22 | Sniffin’ Sticks |
| Cluster headache | Samancı et al., 2021 | 57 | Sniffin’ Sticks |
| Corticobasal syndrome | Luzzi et al., 2007 | 7 | Odour Perception and Semantics Battery |
| COVID-19 | Vaira et al., 2020 | 150 | CCCRC olfaction test |
| Creutzfeldt-Jakob disease | Reuber et al., 2001 | 1 | Unnamed test |
| Cystic fibrosis | Di Lullo et al., 2020 | 121 | Sniffin’ Sticks |
| Depression (unipolar) | Eliyan et al., 2021 | 3546 | Sniffin’ Sticks |
| Down syndrome | Cecchini et al., 2016 | 56 | Sniffin’ Sticks |
| Dystonia | Marek et al., 2018 | 198 | Sniffin’ Sticks |
| Epilepsy | Khurshid et al., 2019 | 912 | UPSIT, Sniffin’ Sticks, other tests |
| Essential tremor | Elhassanien et al., 2021 | 46 | Sniffin’ Sticks |
| Fibromyalgia | Amital et al., 2014 | 45 | Sniffin’ Sticks |
| Fragile X syndrome | Juncos et al., 2012 | 83 | UPSIT |
| Friedreich ataxia | Connelly et al., 2002 | 35 | UPSIT |
| Frontotemporal dementia | Luzzi et al., 2007 | 11 | Odour perception and semantics battery |
| Gaucher disease | McNeill et al., 2012 | 60 | UPSIT |
| HIV/AIDS | Zucco and Ingegneri, 2004 | 48 | UPSIT |
| Huntington’s disease | Fernandez-Ruiz et al., 2003 | 162 | UPSIT |
| Idiopathic intracranial hypertension | Bershad et al., 2014 | 38 | UPSIT, Sniffin’ Sticks, other tests |
| Inflammation | Schubert et al., 2015 | 1611 | San Diego odor identification test |
| Kallmann syndrome | Gregson and Smith, 1981 | 26 | Campbell Gregson procedure |
| Lewy body dementia | Yoo et al., 2018 | 217 | Cross-cultural smell identification test |
| Memory loss with aging | Doty et al., 1984 | 1995 | UPSIT |
| Migraine headaches | Whiting et al., 2015 | 100 | UPSIT |
| Mild cognitive impairment | Peters et al., 2003 | 100 | Sniffin’ Sticks |
| Multiple sclerosis | Atalar et al., 2018 | 55 | CCCRC olfactory test |
| Multiple-system atrophy | Abele et al., 2003 | 8 | Sniffin’ Sticks |
| Myasthenia gravis | Leon-Sarmiento et al., 2012 | 27 | Spanish UPSIT |
| Myotonic dystrophy | Masaoka et al., 2011 | 7 | T&T olfactometer |
| Narcolepsy | Buskova et al., 2010 | 66 | UPSIT |
| Niemann-Pick | Mishra et al., 2016 | 2 | Not indicated |
| OCD | Berlin et al., 2017 | 30 | UPSIT, hedonics and intensity |
| Parkinson’s disease | Haehner et al., 2009 | 50 | Sniffin’ Sticks |
| Long covid | Burges Watson et al., 2021 | 9000 | Self-report |
| Posterior cortical atrophy | Witoonpanich et al., 2013 | 15 | UPSIT |
| Posttraumatic stress disorder | Vasterling et al., 2000 | 68 | UPSIT |
| Prenatal alcohol syndrome | Bower et al., 2013 | 16 | San Diego odor identification test |
| Progressive supranuclear palsy | Shill et al., 2021 | 281 | UPSIT |
| Pure autonomic failure | Goldstein and Sewell, 2009 | 51 | UPSIT |
| REM sleep behavior disorder | Iranzo et al., 2021 | 140 | UPSIT |
| Repetitive head impacts | Alosco et al., 2017 | 123 | Brief smell identification test |
| Schizophrenia | Kopala et al., 1993 | 98 | UPSIT |
| Semantic dementia | Luzzi et al., 2007 | 20 | Odor naming |
| Spinocerebellar ataxias | Abele et al., 2003 | 24 | Sniffin’ Sticks |
| Stroke | Wehling et al., 2015 | 78 | Sniffin’ Sticks |
| Systemic lupus erythematosus | Schoenfeld et al., 2009 | 100 | Sniffin’ Sticks |
| Systemic sclerosis | Amital et al., 2014 | 65 | Sniffin’ Sticks |
| Tourette syndrome | Kronenbuerger et al., 2018 | 56 | Sniffin’ Sticks |
| Traumatic brain injury | Frasnelli et al., 2016 | 63 | Sniffin’ Sticks |
| Usher syndrome | Ribeiro et al., 2016 | 130 | Sniffin’ Sticks |
| Vascular dementia | Suh et al., 2020 | 1 | Korean Sniffin’ Sticks |
| Wilson’s disease | Chen L. et al., 2021 | 50 | UPSIT |
| Zika/Guillain-Barré syndrome | Lazarini et al., 2022 | 38 | Sniffin’ Sticks |